LXR uboot/drivers/mtd/ubi/misc.c

   1/*
   2 * Copyright (c) International Business Machines Corp., 2006
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12 * the GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17 *
  18 * Author: Artem Bityutskiy (Битюцкий Артём)
  19 */
  20
  21/* Here we keep miscellaneous functions which are used all over the UBI code */
  22
  23#include <ubi_uboot.h>
  24#include "ubi.h"
  25
  26/**
  27 * calc_data_len - calculate how much real data is stored in a buffer.
  28 * @ubi: UBI device description object
  29 * @buf: a buffer with the contents of the physical eraseblock
  30 * @length: the buffer length
  31 *
  32 * This function calculates how much "real data" is stored in @buf and returnes
  33 * the length. Continuous 0xFF bytes at the end of the buffer are not
  34 * considered as "real data".
  35 */
  36int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
  37                      int length)
  38{
  39        int i;
  40
  41        ubi_assert(!(length & (ubi->min_io_size - 1)));
  42
  43        for (i = length - 1; i >= 0; i--)
  44                if (((const uint8_t *)buf)[i] != 0xFF)
  45                        break;
  46
  47        /* The resulting length must be aligned to the minimum flash I/O size */
  48        length = ALIGN(i + 1, ubi->min_io_size);
  49        return length;
  50}
  51
  52/**
  53 * ubi_check_volume - check the contents of a static volume.
  54 * @ubi: UBI device description object
  55 * @vol_id: ID of the volume to check
  56 *
  57 * This function checks if static volume @vol_id is corrupted by fully reading
  58 * it and checking data CRC. This function returns %0 if the volume is not
  59 * corrupted, %1 if it is corrupted and a negative error code in case of
  60 * failure. Dynamic volumes are not checked and zero is returned immediately.
  61 */
  62int ubi_check_volume(struct ubi_device *ubi, int vol_id)
  63{
  64        void *buf;
  65        int err = 0, i;
  66        struct ubi_volume *vol = ubi->volumes[vol_id];
  67
  68        if (vol->vol_type != UBI_STATIC_VOLUME)
  69                return 0;
  70
  71        buf = vmalloc(vol->usable_leb_size);
  72        if (!buf)
  73                return -ENOMEM;
  74
  75        for (i = 0; i < vol->used_ebs; i++) {
  76                int size;
  77
  78                if (i == vol->used_ebs - 1)
  79                        size = vol->last_eb_bytes;
  80                else
  81                        size = vol->usable_leb_size;
  82
  83                err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
  84                if (err) {
  85                        if (err == -EBADMSG)
  86                                err = 1;
  87                        break;
  88                }
  89        }
  90
  91        vfree(buf);
  92        return err;
  93}
  94
  95/**
  96 * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad
  97 * eraseblock handling.
  98 * @ubi: UBI device description object
  99 */
 100void ubi_calculate_reserved(struct ubi_device *ubi)
 101{
 102        ubi->beb_rsvd_level = ubi->good_peb_count/100;
 103        ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
 104        if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
 105                ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
 106}
 107